Silicon based semiconducting devices have been around for some time for defining p-n structures, such as used in diodes, bipolar transistors and high voltage transistors. Silicon structures have limitations in electrical and optical properties.
Recent efforts have been made in obtaining semiconductor devices that do not rely on the properties of silicon. Particularly, attention has been directed to III-V compounds, and more particularly, attention has recently been directed at Galium Nitride (GaN) compounds.
For example, various high electron mobility transistors, light emitting diodes and MIS types of transistors have been disclosed in U.S. Pat. Nos. 5,192,987 and 5,122,845, as well as Japanese Published Application Number 3-273632. These prior references provide GaN type transistor structure that work in the depletion zones with n-conducting layers or are used in an insulating capacity.